Circuit breaker with indicator of breaker position

ABSTRACT

A circuit breaker includes a frame defining a housing having an interior compartment and a circuit interrupter. An actuator is connected to the circuit interrupter and configured to actuate the circuit interrupter into closed and open breaker positions. An indicator is connected to the actuator and movable between first and second positions corresponding to the respective closed and open breaker positions. A first indicator surface has first indicia indicative that the circuit interrupter is in the closed breaker position and a second indicator surface having second indicia indicative that the circuit interrupter is in the open breaker position. An opening is formed on the housing and aligned with the indicator to expose for view the respective first or second indicia when the circuit interrupter is in the respective closed or open breaker position.

PRIORITY APPLICATION(S)

This utility application is based upon U.S. provisional application Ser.No. 63/363,318 filed Apr. 21, 2022, the disclosure which is herebyincorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to the field of electrical systems, andmore particularly, this invention relates to circuit breakers.

BACKGROUND OF THE INVENTION

Medium voltage indoor and outdoor circuit breakers and associatedswitchgear systems typically operate as three-phase systems that connectto the three-phase power distribution grid and provide protectionagainst an undesirable circuit condition, such as short circuit eventsand similar overcurrent or other fault conditions. They often includecircuit interrupters, such as vacuum interrupters, that open and closeindividual circuits. In many circuit breakers, the vacuum interruptersare normally fixed within the housing. A magnetic actuator may becarried by the vacuum interrupter and has the biasing force to operatethe vacuum interrupters. A permanent magnetic actuator may have one ormore permanent magnets and electric energy is applied to a coil to movea core or other mechanism into a stroke position which may open or closethe contacts in a vacuum interrupter.

Permanent magnetic actuators can be formed as a bistable or mono-stablemagnetic actuator depending on how their operating mechanism works andhow any core or other mechanism is held at a preset position. A bistabletype permanent magnetic actuator permits the core to be held at each ofboth ends of a stroke of the core due to the permanent magnets. Amono-stable type permanent magnetic actuator, on the other hand, isconfigured such that the core is held at only one of both ends of astroke. Because a bistable type permanent magnetic actuator holds anycore in a preset position by the magnetic energy imparted from thepermanent magnets upon opening or closing the vacuum interrupter, thebistable actuator is considered by some skilled in the art to be betteradapted for use with some circuit breakers. However, these magneticactuators usually operate one latch connector or other common jack shaftthat interconnect and switch open and closed three vacuum interruptersused in a three-phase electrical system. Single-phase operation isunworkable.

There are circumstances, especially with both indoor and outdoor circuitbreakers and some switchgear systems, in which a quick visualdetermination is advantageous to determine whether the circuitinterrupter is in a closed or open breaker position. Workers andmaintenance personnel are often in a hurry to operate or maintaincircuit breakers. Having the ability to discern quickly whether thecircuit interrupter is in the closed or open breaker position could belifesaving in some circumstances to prevent inadvertent mistakes whenthe circuit breaker is in the closed breaker position and “hot.”

Additionally, with outdoor circuit breakers, terminal bushings arereceived within bushing openings located on the outer surface, such asat the top of the housing roof. These terminal bushings are formed of aceramic material while the clamps, bolts and the outer surface, such asthe outer surface or roof through which the terminal bushings arereceived, are formed of a metallic material such as aluminum having amuch different coefficient of thermal expansion (CTE) than the ceramicmaterial. The ceramic terminal bushings do not change dimensionthroughout the extreme temperature variations, ranging from −40° to 140°Fahrenheit. However, the clamps, roof and bolts change dimensions inextreme temperature variations and cause leaks around the terminalbushings, which can create dangerous short circuits or damage internalcomponents contained within the outdoor circuit breaker.

SUMMARY OF THE INVENTION

This summary is provided to introduce a selection of concepts that arefurther described below in the Detailed Description. This summary is notintended to identify key or essential features of the claimed subjectmatter, nor is it intended to be used as an aid in limiting the scope ofthe claimed subject matter.

In general, a circuit breaker may comprise a frame defining a housinghaving an interior compartment and at least one circuit interrupterfixed within the interior compartment and having closed and open breakerpositions. An actuator may be mounted within the interior compartmentand connected to the at least one circuit interrupter and configured toactuate the at least one circuit interrupter into the closed and openbreaker positions. An indicator may be connected to the actuator andmovable between first and second positions corresponding to therespective closed and open breaker positions. The indicator may have afirst indicator surface having first indicia indicative that the atleast one circuit interrupter is in the closed breaker position and asecond indicator surface having second indicia indicative that the atleast one circuit interrupter is in the open breaker position. Anopening may be formed on the housing and aligned with the indicator toexpose for view the respective first or second indicia when the at leastone circuit interrupter is in the respective closed or open breakerposition.

A light guide may be mounted adjacent the opening within the housing andconfigured to guide light from outside the housing onto the indicator.The light guide may comprise a light tunnel having a light entrance atthe opening and extending within the housing and a light exit adjacentthe indicator. The light tunnel may comprise an interior reflectivesurface. The first indicia may comprise a first color and the secondindicia comprises a second color. A pivot arm may have a first endcooperating with the actuator and a second end connected to theindicator. The actuator may include a movable output and actuator plateconnected thereto, wherein the first end of the pivot arm is biasedagainst the actuator plate. The actuator may comprise a magneticactuator configured to receive an open or close signal and in response,actuate the at least one circuit interrupter connected thereto into anopen or closed circuit condition.

The frame and housing may be configured as an outdoor circuit breaker orindoor circuit breaker. The at least one circuit interrupter maycomprise first, second and third single-phase circuit interrupters fixedwithin the interior compartment, each having closed and open breakerpositions, and respective first, second and third actuators connected torespective first, second and third single-phase circuit interrupters.The first, second and third indicators may be connected to therespective first, second and third actuators, and first, second andthird openings formed on the housing and may be aligned with respectivefirst, second and third indicators.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the present invention willbecome apparent from the Detailed Description of the invention whichfollows, when considered in light of the accompanying drawings in which:

FIG. 1 is an isometric view of a circuit breaker, and in this example,an outdoor circuit breaker according to the invention.

FIG. 2 is a front elevation view of the circuit breaker of FIG. 1 .

FIG. 3 is an isometric view of the circuit breaker of FIG. 1 cut along avertical side sectional elevation.

FIG. 4 is another isometric view of the circuit breaker of FIG. 1 cutalong another vertical side sectional elevation different from that ofFIG. 3 .

FIG. 5 is a sectional view of the upper high-voltage compartment of thecircuit breaker of FIG. 1 showing a vacuum interrupter and terminalbushing connected thereto.

FIG. 6 is an enlarged sectional view of a terminal bushing shown in FIG.5 .

FIG. 7 is another enlarged sectional view of the terminal bushing shownin FIG. 6 .

FIG. 8 is another enlarged sectional view of the terminal bushing shownin FIG. 6 and showing in detail the dynamic seal contained within theseal pocket.

FIG. 9 is a fragmentary isometric view of a portion of the interior ofthe circuit breaker and the indicator operated by the actuator.

FIG. 10 is a sectional view of a portion of the circuit breaker showingthe actuator and indicator.

FIG. 11 is an enlarged sectional view of the actuator and indicatorshown in FIG. 11 .

FIG. 12 is another enlarged sectional view of the indicator of FIG. 11and showing in detail the light tunnel.

FIG. 13 is a block diagram of a three-phase power distribution grid anda medium-voltage circuit breaker having single-phase breaker controlusing magnetic actuators in accordance with a non-limiting example.

FIG. 14 is an isometric view of an example magnetic actuator that may beused in the circuit breaker shown in FIGS. 3, 4, 9, and 13 .

FIG. 15 is another isometric view of the magnetic actuator of FIG. 14 ,but showing permanent magnets located behind the side plates that arepictured in a transparency view.

FIG. 16 is an exploded isometric view of the magnetic actuator of FIGS.14 and 15 .

DETAILED DESCRIPTION

Different embodiments will now be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsare shown. Many different forms can be set forth and describedembodiments should not be construed as limited to the embodiments setforth herein. Rather, these embodiments are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope to those skilled in the art.

Referring now to FIGS. 1-4 , there are illustrated different views of amedium-voltage circuit breaker, formed in this example as an outdoorcircuit breaker with single phase control and indicated generally at100, which includes a frame 104 defining a switchgear housing 106 havingan interior compartment 110 (FIGS. 3 and 4 ) and an outer surface 114,which includes a roof having a top surface. Bushing openings 118 areformed on the outer surface and receive a plurality of terminal bushings120 within the bushing openings as illustrated by the first, second andthird sets, each with two for a total of six terminal bushings shown inFIG. 1 . The terminal bushings 120 may be received on any outer surface114 of the switchgear housing, such as the side surface or top surfaceas a roof.

As will be explained in detail below, selected terminal bushings 120electrically connect to the three-phase power grid 224 (FIG. 13 ) and tothe loads, such as different street zones 220, and connect to circuitinterrupters 124 operable as circuit breakers that are mounted andusually fixed within the interior compartment 110. Each circuitinterrupter 124 includes a first upper and a second lower terminal 124a,124 b (FIGS. 3 and 4 ) and each in an example may be formed as vacuuminterrupters. First, second and third vacuum interrupters 124 correspondto first, second and third sets of terminal bushings 120. In thisexample, the outer surface 114 may be made from aluminum and otherportions of the outdoor housing 106 may be formed of aluminum or othermetallic material as non-limiting examples. A lever 126 is positioned onthe side of the outdoor housing 106 for actuation of components and mayeven be configured for emergency circuit breaking.

As shown in the front elevation view of the circuit breaker 100 in FIG.2 , the lower section of the housing corresponds to a low voltagecompartment 128 and includes an access door 130 to that low voltagecompartment that may be locked, but easily accessed via a door handle132. The upper high-voltage compartment 136 is more secure, but may beaccessed by removing bolts or other fasteners 138 on the upper frontpanel 140.

As will be explained in greater detail below, openings forming threeview windows 142 are aligned horizontally above the access door 130 andaligned with three respective indicators 144 (two shown in FIG. 9 ) toexpose for view respective first or second indicator surfaces 176 a,176b (FIG. 12 ) positioned on each respective indicator to indicate whenone or more of the circuit interrupters 124 in this example are inrespective closed or open breaker positions. In this example, the frame104 that defines the outdoor housing 106 is supported on a stand 148that includes adjustable cross-members 150 and legs 152 that may beadjusted to vary the height of the outdoor housing 106. The upperportion of the housing corresponding to the upper high-voltagecompartment 136 includes the three different vacuum interrupters 124that each have closed and open breaker positions to form the three-phasecircuit breaker 100 having single phase control, which in this exampleis an outdoor circuit breaker.

In this example, each circuit interrupter 124 is mounted in a fixedarrangement within the interior compartment 110 at an angle (FIGS. 4 and5 ) and each includes its respective first and second terminals 124a,124 b. In this three-phase circuit breaker 100, the three differentcircuit interrupters 124 are formed as vacuum interrupters. Eachrespective circuit interrupter 124 provides operation as a circuitbreaker for one of the phases in the three phases. Each circuitinterrupter 124 is mounted within the interior compartment 110 at anangled position relative to the vertical height of the outdoor housing106 as best shown in FIGS. 3 and 4 to reduce the overall vertical heightof the circuit breaker 100 and permit better connection of each vacuuminterrupter to one of its sets of terminal bushings 120.

For each respective vacuum interrupter 124, first and second terminalbushings 120 are received within first and second bushing openings 118and form one of the three sets. Each terminal bushing 120 has an upperterminal end 120 a extending upward from the outer surface 114 as theroof in this example (but could be a side wall) and a lower terminal end120 b extending into the housing 106. The lower terminal end 120 b iselectrically connected to one of first or second terminals 124 a,124 bon each of the circuit interrupters 124 as illustrated in FIGS. 3 and 4, depending on what the upper terminal end 120 a for a respectiveterminal bushing connects, such as the power grid 224 or the load 220 asstreet zones, for example (FIG. 13 ). Each vacuum interrupter 124 hasconnected thereto an actuator 234, formed as a magnetic actuator in thisexample (FIGS. 9-12 and 14-16 ) and mounted within the interiorcompartment 110 and connected to its respective vacuum interrupter andconfigured to actuate the vacuum interrupter into closed and openbreaker positions.

An internal divider 154 (FIGS. 3-5 ) separates the upper, high-voltagecompartment 136 from the lower, low-voltage compartment 128. Asillustrated, each terminal bushing 120 in this non-limiting exampleincludes a slip-over current transformer 156 (FIGS. 3-8 ) positionedjust below the roof 114 inside the outdoor housing 106. These currenttransformers 156 slip around the respective terminal bushing 120 tocenter the conductor of the current transformer 156 inside the “window”of the current transformer formed as a circular central opening and areconfigured to measure voltage and/or current. The current transformer156 may operate as a sensing circuit 260 (FIG. 13 ) to aid in detectingan undesirable circuit condition, but other sensing circuits may beused, including resistive or capacitive voltage sensors, different typesof transformers, Rogowski coils and other types of sensors. The firstterminal 124 a of the vacuum interrupter 124 may connect to a terminalbushing 120 that connects to incoming power.

Each terminal bushing 120 has its lower terminal end 120 b extendinginto the outer housing 106 and electrically connected to one of thefirst or second terminals 124 a,124 b of the respective vacuuminterrupter 124 to which it is grouped as best shown in FIG. 4 , where aterminal connector 158 similar to a bus bar connects the lower end 120 bof a terminal bushing 120 with a terminal on the vacuum interrupter 124.The low-voltage compartment 128 may include auxiliary switches and othermechanical mechanisms (not shown) for operational adjustment, andinclude different mounting panels and control equipment, which areusually all accessible via the access door 130.

As illustrated in greater detail FIGS. 5-8 , the terminal bushings 120are received within the bushing openings 118, and in accordance with anon-limiting example, each terminal bushing 120 may include an outerflange 160 that forms a bushing seat that positions the respectiveterminal bushing 120 against and adjacent the outer surface 114, and inthis example as illustrated, the top surface of the roof at the bushingopening. Mounting bolts 162 in this example are secured from theunderside of the top surface of the roof 114, such as by welding, andextend upward adjacent the outer flange 160. In the example as bestshown in FIG. 1 , four mounting bolts 162 are positioned at 90° aroundthe outer flange 160 that forms the bushing seat. The mounting boltsreceive a mounting clamp 164 that engages the top surface of the outerflange 160. A nut is secured on each mounting bolt 162 to secure theterminal bushing 120 onto the outer surface 114, and in this example,the roof.

Each terminal bushing 120 includes a gasket 166 operative as a seal, asbest shown in the enlarged sectional views of FIGS. 7 and 8 . Thisgasket 166 may be a vendor provided gasket, although it is not necessaryto be vendor provided and may be custom designed. In many conventionalterminal bushing sealing techniques for outdoor circuit breakers,caulking is applied onto any vendor provided gaskets, which is usuallyformed from an elastomeric polymeric material, and together with thecaulking, is used in an attempt to seal a terminal bushing 120 toprevent leakage of water and other foreign matter into the outdoorhousing 106. However, any conventional mounting clamp, any fastenerssuch as bolts and nuts, and the outer surface, such as the roof of thehousing 106, are formed from a first material, such as aluminum, havinga first coefficient of thermal expansion, while the terminal bushings120 are each formed of a second material having a secondary coefficientof thermal expansion, such as ceramic. Of course, steel and othermaterials may be used.

Circuit breaker components formed from a material, such as ceramic, donot change in dimension due to temperature variations as readily asthose components formed from a material, such as steel, aluminum, orsimilar material. Thus, the temperature differentiation that may existin outdoor circuit breakers such as from a low of −40° Fahrenheit to ahigh of 140° Fahrenheit under normal operating conditions are often sogreat that leakages occur because the caulking in conventional outdoorbreaker configurations does not hold. Thus, in conventional outdoorcircuit breakers, a good seal is not provided.

Compression on one side of a terminal bushing 120, such as created bycantilever forces exerted by connected cables, may cause the other sideof the terminal bushing to lift. As a result, moisture may enter theoutdoor circuit breaker 100 via its outer surface 114, such as the roofof the housing 106, and via the bushing openings 118, and cause damageto components inside the housing and create hazardous operatingconditions.

In accordance with a non-limiting example, a spacer 168 in this exampleis positioned between the upper gasket 166 and the top surface of theroof 114, and configured to form a seal pocket 170 bounded by thebushing opening 118, the upper gasket 166, the spacer 168 and an outersurface of the terminal bushing 120. The spacer 168 is optional, andinstead of using the spacer, a forming tool may be employed to form theseal pocket 170 by crimping or deforming the outer surface, such as theroof.

As illustrated best in FIG. 8 showing in greater and enlarged detail theseal pocket 170, a dynamic seal 172 is contained in the seal pocket andcompressed in an amount sufficient to provide elasticity and acompression height for dynamic loading of the upper gasket 166. In anexample, it is possible to obtain at least about 0.05 inches (about 1/16inch) dynamic movement before the dynamic seal 172 opens up the jointand allows water or other foreign material leakage through the bushingopenings 118 into the interior compartment 110.

The dynamic seal 172 may be formed as an O-ring such as from anelastomeric material, and it may be compressed about 20% to 40% whenreceived within the seal pocket 170, and in this example, about 30%, andthus, impart dynamic resilience. In another example, the dynamic seal172 may be formed as a C-shaped seal having a spring therein. When thespacer 168 is employed, instead of using a crimp or other forming toolto help form the seal pocket 170, the spacer is usually formed of thefirst material having a first coefficient of thermal expansion, such asaluminum, so that it has the same expansion and contraction in sizeproportional to the mounting bolts 162 and their nuts, the outer surface114 such as the roof, and the mounting clamp 164, which also in thisexample are also formed of aluminum. Thus, the configuration of thedynamic seal 172 in the sealing pocket 170 provides added protectionagainst common leakage issues related to the terminal bushings 120received in bushing openings 118, a problem that plagues mostconventional outdoor circuit breakers.

Referring now to FIGS. 9-12 , there is illustrated an example of anindicator 176 that is operable via an actuator 234, in this example, amagnetic actuator, and movable between first and second positionscorresponding to respective closed and open breaker positions. Theindicator 176 has a first indicator surface 176 a with a first indiciasuch as a red color on its surface and a printed text word, such as“CLOSED” indicative that the at least one circuit interrupter as anexample vacuum interrupter 124 is in a closed breaker position. A secondindicator surface 176 b has a second indicia indicative that the atleast one vacuum interrupter 124 is in the open breaker position. Thesecond indicator surface 176 b could be a green color and the word“OPEN” displayed thereon indicative that the particular circuitinterrupter tripped open, for example.

In this example, a pivot arm 178 (FIG. 9 ) has a first end 178 acooperating with the magnetic actuator 234 via an actuator plate 316 anda second end 178 b connected to the indicator 176, which in thisillustrated example is formed as a curved plate that has an uppersection and a lower section corresponding to the respective first andsecond indicator surfaces 176 a,176 b having the first and secondindicia. The magnetic actuator 234 includes a movable output 314 formedas a cylindrical member that supports the actuator plate 316 as bestshown in the enlarged isometric view of FIG. 9 , which moves relative tothe fixed section of the magnetic actuator and imparts the driving forceto the first end 178 a of the pivot arm 178, which is biased against theactuator plate 316.

As shown in FIGS. 9 and 12 , a light guide is formed in this example asa light tunnel 180 and is mounted adjacent to a respective openingforming a view window 142 within the outdoor housing 106 (FIGS. 1 and 12) and configured to guide light from outside the outdoor housing ontothe particular first or second indicator surface 176 a,176 b that ispivoted to be adjacent and in view to a user from the light tunnel 180.This light tunnel 180 has a light entrance 180 a adjacent the opening asthe view window 142, and in this example, set back a short distance,such as one to two inches (FIG. 12 ), and extends within the outdoorhousing 106 to a light exit 180 b that is adjacent the indicator 176 anddimensioned so that the opening defined by the light entrance 180 a ofthe light tunnel is larger than the light exit 180 b.

Light is guided from the light entrance 180 a to the light exit 180 b.The light tunnel 180 as a manufactured component may be formed fromadditive manufacturing techniques and may include an internal reflectivesurface coating 180 c similar to a chrome mirror. The light tunnel 180may be a 3D printed component. In this example, the light tunnel 180 issubstantially rectangular configured as illustrated and tapers from thelarger light entrance 180 a to the smaller light exit 180 b, such thatin combination with the internal reflective surface 180 c, light isguided onto the indicator 176. A mounting flange 182 formed at the lightentrance 180a secures the light tunnel 180 at the opening (FIG. 12 ) asthe view window 142 through which an individual may view the first orsecond indicia on the respective surface 176 a,176 b of the indicator176, depending on how the indicator is pivoted to determine visuallywhether the vacuum interrupter 124 is in the closed or open breakerposition. In this example, three indicators 176 are mounted inside-by-side relation and cooperate with a respective magnetic actuator234, one for each indicator, corresponding to the three phases.

As illustrated best in FIG. 9 , the pivot arm 178 is formed as a leverand supported for pivotal movement by a support assembly 184 thatincludes a bracket or other support and may be secured to the magneticactuator 234 and other frame 104 and support components. The pivot arm178 may be supported for pivotal movement on the support assembly 184via a pivot pin or other mechanism. The first end 178 a of that pivotarm 178 is angled to be biased against the actuator plate 316. When themagnetic actuator 234 receives an open or close signal, in an example,the open signal in response, the magnetic actuator “breaks” the vacuuminterrupter 124 connected thereto into an open circuit condition. Theactuator plate 316 moves down via its movable output such as part of adrivable shaft of the magnetic actuator 234 to which it is connected.

The pivot arm 178 may be biased by a spring mechanism 186 (FIG. 11 ),which may force the second end 178 b of the pivot arm 178 to move thesecond indicator surface 176 b and the second color, e.g., green and the“OPEN” word adjacent the light entrance 180 a of the light tunnel 180.As shown in FIGS. 10 and 11 , various electronic components 188, such ascontrol electronics, may be positioned within the high-voltagecompartment 136 adjacent to each magnetic actuator 234. The indicator176 thus provides a readily available indicia that a user may view withlittle difficulty and determine with a quick visual glance whether aparticular vacuum interrupter 124 is in a closed or open position.

Referring now to FIG. 13 , there is illustrated a schematic diagram ofthe medium-voltage circuit breaker 100, such as an outdoor circuitbreaker, but could be an indoor circuit breaker. The circuit breaker 100is incorporated within a three-phase power distribution grid 224 thatincludes a three-phase input 228 having first, second and thirdsingle-phase input circuits 228 a, 228 b, 228 c into the medium-voltagecircuit breaker. The circuit breaker 100 may be formed to be placedoutdoors, although it is possible to use the equipment for indoor usewith associated indoor switchgear systems. The circuit breaker 100includes single phase breaker control that allows the circuit breaker toprovide single-phase control over one or two or all three single-phaselines, and in an example of selectively opening and closing one, twoand/or three lines. In an example, power may be maintained on aremaining single-phase line such as for powering an outdoor street zoneas part of a neighborhood, or power part of a residential tower when theother one or two of the other single-phase lines may go down. In thisexample, the magnetic actuators 234 are shown schematically by M1, M2and M3 and given the designation 234 a, 234 b, 234 c, and actuateopening or closing of contacts within the first, second and third vacuuminterrupters indicated at 238 a, 238 b, 238 c.

Other neighborhoods or street sections may form the load 220 and areschematically illustrated by the outdoor street zones numbered one tothree forming respective single phase loads 220 a, 220 b, 220 c. Forexample, the first outdoor street zone 220 a may have its power cut offwhen the first single-phase line 220 a is dropped, such as throughovercurrent or short circuit as a non-limiting example, but the othertwo outdoor street zones 220 b,220 c may be supplied by the other twosingle-phases, i.e., the second and third single phases, and thus, powerremains on those two street zones. For example, the first single phaseoutdoor street zone 220 a may have a short circuit in that single-phasesegment, such as when a power line may have been downed. Thatsingle-phase may be tripped at the single-phase pole, e.g., at thevacuum interrupter 238 a for that phase, but the two other second andthird single phase outdoor street zones 220 b,220 c may have powerprovided from the other two single phase circuits because the controller250, which may be a relay as explained below, ensured that those vacuuminterrupters 238 b,238 c remain in a closed operative state and maintainpower to those street zones. It should be understood that one controlleror relay 250 may be used or individual controllers or relays 250 foreach of the three phases with various types of relay circuits employed.In FIG. 13 , individual relays or controllers may be used as shown bythe block designation 250 a, 250 b, 250 c, having a respective open (o)or close (c) signal output to a respective magnetic actuator. Acontroller 250 having microprocessor functions may be configured tooperate as a relay.

The circuit breaker 100 may include components common to many circuitbreakers, such as the frame shown by the solid line at 242 forming thehousing and having an interior compartment shown at 243 and an outersurface with terminal bushings 245 a, and the three-phase inputs 228 a-cconnected to the respective first, second and third single-phasecircuits of the three-phase power distribution grid 224. The circuitbreaker 100 has first, second and third single-phase outputs 244 a, 244b, 244 c that output the three phases via terminal bushings 245 a. In anoutdoor circuit breaker 100, there is no truck, and instead, the vacuuminterrupters 238 are fixed inside an outdoor housing (FIG. 1 ).

The three-phase circuit breaker 100 includes the first, second and thirdsingle-phase vacuum interrupters 238 a, 238 b, 238 c, where two areshown in the isometric cut-away view of FIG. 4 (and given designation124), and configured to be connected between the respective first,second and third single-phase inputs 228 a, 228 b, 228 c and first,second and third single-phase outputs 244 a, 244 b, 244 c as shown inFIG. 13 . A first magnetic actuator M1 234 a is connected to the firstsingle-phase vacuum interrupter 238 a. A second magnetic actuator M2 234b is connected to the second single-phase vacuum interrupter 238 b. Athird magnetic actuator M3 234 c is connected to a third single-phasevacuum interrupter 238 c. Each magnetic actuator M1 234 a, M2 234 b, M3234 c may be configured to receive an open or close signal from arespective relay or controller 250, and in response, actuate therespective vacuum interrupter 238 a, 238 b, 238 c connected thereto intoan open or closed circuit condition.

The relay or controller 250 as it may sometimes be employed is connectedto each of the first, second and third magnetic actuators M1 234 a, M2234 b, M3 234 c, and configured to generate the open or close signal toa respective magnetic actuator in response to an undesirable circuitcondition detected on a minimum of single-phase circuit as part of theload 220. For example, the relay or controller 250 may send an opensignal to a magnetic actuator 234 and open that single-phase circuit onwhich the undesirable circuit condition was detected. A sensing circuit260, such as initially described above or other sensing circuits, may beconfigured to detect the undesirable circuit condition. The sensingcircuit 260 may include a current sensor, a potential or voltage sensoror both, and may be within the circuit breaker 100 as local to thedevice or remote from the device and positioned in the field, forexample. One or more vacuum interrupters 238 a, 238 b, 238 c may receiveopen or close commands from the controller 250. Power may be maintainedon one or more of the remaining single-phase circuits over which asingle-phase undesirable circuit condition was not detected.

One controller or relay 250 may be used and may be positioned inside thecircuit breaker 100 or separate units 250 a, 250 b, 250 c may be used tocommunicate and transmit open and close signals to the magneticactuators 234 a, 234 b, 234 c. When multiple controllers or relays 250are used, a first controller or relay 250 a may be connected to thefirst magnetic actuator M1 234 a. A second controller or relay 250 b maybe connected to the second magnetic actuator M2 234 b. A thirdcontroller or relay 250 c may be connected to the third magneticactuator M3 234 c. In another example, the controller or relay 250 maybe formed as a single module mounted local, i.e., within the interiorcompartment 243, or mounted remote such as outside the interiorcompartment and connected to each of the first, second and thirdmagnetic actuators M1 234 a, M2 234 b, M3 234 c.

The loads may include first, second and third single-phase loads 220 a,220 b, 220 c and are connected to respective first, second and thirdsingle-phase outputs 244 a, 244 b, 244 c, such as the different outdoorstreet zones for different groups of residential houses. Each may havean electrical demand operating with single-phase. For example, the firststreet zone 220 a may be powered by the first single-phase line, thesecond street zone 220 b may be powered by the second single-phase line,and the third street zone 220 c may be powered by the third single-phaseline. In another example, it is possible to have first, second and thirdloads that may be a business that uses three-phase power and a group ofhomes that use a single-phase power.

As noted before, a sensing circuit 260 may be configured to detect theundesirable circuit condition on a minimum of a single-phase circuit.The sensing circuit 260 may be formed as three separate sensing circuitsconnected either local or remote to the circuit breaker. In an example,three sensing circuits 260 may connect to respective three terminalbushings, and could be a Rogowski coil, a current sensor, a potentialsensor or both, or a capacitive or resistive voltage sensor. The sensingcircuit 260 is connected to the controller/relay 250, which may generatean open or close signal on three sets of open or three sets of closesignal lines and signals a respective magnetic actuator M1 234 a, M2 234b, M3 234 c to actuate and move the movable contact of the respectivevacuum interrupter 238 a, 238 b, 238 c into open or closed circuitpositions in this example. The controller/relay 250 may include thethree different individual controller or relay circuits 250 a, 250 b,250 c for each respective magnetic actuator 234 a, 234 b, 234 c, andgenerate respective close and open signals. The sensing circuit 260 maysend proportioned signals for the controller/relay 250.

Referring again to FIGS. 4 and 5 , there are illustrated schematicsectional views of a vacuum interrupter 124 and operated by the examplemagnetic actuator 234, which may correspond to any one of the threemagnetic actuators 234 a, 234 b, 234 c shown in FIG. 13 . Themedium-voltage vacuum interrupter 124 shown schematically in FIG. 5includes an inner fixed electrical contact 125 a and a correspondingmovable electrical contact 125 b shown by dashed lines and form theswitch or circuit breaker for electrical power interruption. The movableelectrical contact 125 b moves between a closed and open position via aconnector, which in an example, may be termed an insulating contactshaft 125 c that connects to an output shaft 314 as shown in FIG. 16 .The vacuum interrupter 124 (FIG. 5 ) and magnetic actuator 234 aremounted in the circuit breaker 100 as an example outdoor circuit breakeras noted before, and angled relative to the vertical as shown in FIG. 5. The vacuum interrupter's fixed contact 125 a forms a fixed terminal atthe top that connects to a lower terminal end 120 b of a terminalbushing 120 (FIG. 5 ).

The movable contact 125 b may connect to a lower terminal end 120 b ofthe vacuum interrupter 125, which in turn, connects to a lower terminalend 120 b of another terminal bushing 120 that is associated with theterminal bushing 120 to which the fixed contact is connected. It ispossible that the movable contact 125 b may connect to a flexibleterminal or a sliding contact terminal and lower contact arm. Upper andlower flanges may be included to hold an arc shield as part of aninsulator. The vacuum interrupter 125 may include a bellows shield andbellows. In FIG. 5 , for example, the terminal bushing 120 on the leftmay connect from the power grid 224, and the second terminal bushing onthe right may connect to the load 220.

Referring now to FIGS. 14-16 , further details of the magnetic actuator234 are illustrated, which includes a fixed core 324 and a plurality ofpermanent magnets 304 surrounding the fixed core 324. A movable core 306(FIG. 16 ) is received within the fixed core 324 and includes an outputshaft 314 coupled to a piston 318 and piston plate 328. The plurality ofpermanent magnets 304 are arranged in a rectangular, and in thisexample, a square configuration around the fixed core 324. Eachpermanent magnet may be formed as a bar magnet that extends the lengthof a side forming the rectangular, and in this example, squareconfiguration (FIG. 15 ). In a non-limiting example, each bar magnet asa permanent magnet 304 may be rectangular configured. A side plate 310covers each permanent magnet 304 forming a box configuration. Themovable core 306 includes its output shaft 314 and a piston 318 andmovable within the fixed core 324.

The holding force for the magnetic actuator 234 is developed by thepermanent magnets 304 while an electrical coil 300 that may be formed asa single or multiple winding coil and provides the closing speed andforce that is generated by the coil and amperage flowing in the windingsof the coil. The permanent magnets 304 surrounding the fixed core 324form a toroid of a magnetic field surrounding the fixed core. The outputshaft 314 has an end configured to connect to a connector 280, e.g., theinsulating contact shaft 125 c, as part of the vacuum interrupter 124connected thereto and shown in FIG. 5 .

The exploded isometric view of FIG. 16 shows further details where eachpermanent magnet 304 may be formed as a bar magnet, and in anon-limiting example, may be rectangular configured, and in an example,have dimensions of about 1.0 inch by 4.0 inches and a one-quarter inchthick and formed in this non-limiting example from a machined or castNeodymium Iron Boron magnet (NdFeB or NIB magnet). One or more magnets304 may be used per side depending on design. The permanent magnets 304may be made from this alloy of Neodymium, Iron and Boron in this exampleand created as a 42H magnet grade as a rare-earth sintered neodymiummagnet.

In this example, the magnetic actuator 234 includes an application plate320 that engages a center block as the fixed core 324. Both theapplication plate 320 and center block as the fixed core 324 have acentral, circular opening into which the output shaft 314 is received.The piston 318 engages the piston plate 328 that engages a bottom plate330 when the piston plate moves with the piston toward the bottom plate.The movable core 306 includes the output shaft 314 and is similar to apush rod. The output shaft 314 is secured with a lock nut 334 at thepiston plate 328 and with a flange nut 338 at the other end thatoperates as a connection to the insulating contact shaft 280 alsoreferred to by some as a push rod. The permanent magnets 304 engageagainst the side of the center block as the fixed core 324, which has acylindrical fitting 324 a on which the lower edge of the electrical coil300 may engage. The side plates 310 help form the square configurationas illustrated and are secured in position at the magnetic actuator 234and against the application plate 320 and bottom plate 330 via avibration resistant clamp 340.

A die spring 344 is contained within the piston 318 and is secured andaligned to the piston plate 328 via alignment pin 348. Various fasteners350 are illustrated to hold components together. It is possible toinclude stand-offs (not shown) that allow the magnetic actuator 234 tobe positioned so that it may be connected to a frame or other component.The output shaft 314 may be secured to the insulating contact shaft 280.

In an example, the electrical coil 300 resistance may be about 3.8+/−0.2 ohms and the permanent magnets 304 may include a minimum averageholding force among five readings that is equal to about 9,000 N(Newtons) with a minimum single hold force reading of a four positionrotation of the piston 318 of about 8,900 N. As noted before, theholding force is developed by the permanent magnets 304 and closingspeed and force is generated by the coil 300 and amperage flowing in thewindings. In an example, the magnetic actuator 234 may be formed as an8.5 kN box actuator having a 14 millimeter travel. The output shaft 314may pass through a low coefficient of friction, Teflon (PTFE) sleevebearing 358 (FIG. 16 ) and the die spring 344 has sufficient force forbiasing against movement of the applied magnetic force. The die spring344 biases in the open position.

A controller used for the devices may be connected to a secondaryvoltage that may be present in the outdoor circuit breaker 100 such as100 volts, 200 volts, or 250 volts, which in one example operates off250 volts. A charge capacitor (not shown) in an example may always becharged to 250 volts and a controller may facilitate the connectionbetween the charge capacitor and magnetic actuator 238 to generate themagnetic flux in the coil and move it in the opened and closedcondition. The current is short and creates a very strong magnetic fieldand moves the insulating contact shaft 125 c and moves the movablecontact or terminal 125 b relative to the fixed contact 125 a. Themedium voltage circuit breaker 100 may control 15 kV power in anexample, but may operate from a control voltage of 48, 125, 250 volts DCor 120, 220 volts AC.

The magnetic actuator 234 is compact and because of its configuration ofthe four permanent magnets 304 in a square configuration in this exampleas illustrated, it is efficient and creates a high permanent magneticforce. The use of flat plates for the permanent magnets 304 generate amore uniform toroid for the magnetic field around the fixed core 324. Itis possible that the permanent magnets 304 may be arranged in differentconfigurations besides a square configuration, such as a triangular or apentagon, i.e., five-sided or other configuration. The side plates 310may be formed from a ferromagnetic material to carry the magnetic field.The magnetic actuator 234 as described is an improvement over othermagnetic actuator designs that may include lower and upper plungers orpermanent magnets that may be in a C-shaped armature configuration, oruse stacked sheets or energized coils.

This application is related to copending patent applications entitled,“CIRCUIT BREAKER WITH SINGLE PHASE CONTROL,” and “CIRCUIT BREAKER WITHTERMINAL BUSHINGS HAVING DYNAMIC SEAL,” which are filed on the same dateand by the same assignee and inventors, the disclosures which are herebyincorporated by reference.

Many modifications and other embodiments of the invention will come tothe mind of one skilled in the art having the benefit of the teachingspresented in the foregoing descriptions and the associated drawings.Therefore, it is understood that the invention is not to be limited tothe specific embodiments disclosed, and that modifications andembodiments are intended to be included within the scope of the appendedclaims.

1. A circuit breaker, comprising: a frame defining a housing having aninterior compartment; at least one circuit interrupter mounted withinthe interior compartment and having closed and open breaker positions;an actuator mounted within the interior compartment and connected tosaid at least one circuit interrupter and configured to actuate the atleast one circuit interrupter into the closed and open breakerpositions; an indicator operatively connected to said actuator andmovable between first and second positions corresponding to therespective closed and open breaker positions, said indicator having afirst indicator surface having first indicia indicative that the atleast one circuit interrupter is in the closed breaker position and asecond indicator surface having second indicia indicative that the atleast one circuit interrupter is in the open breaker position; anopening formed on the housing and aligned with the indicator to exposefor view the respective first or second indicia when the at least onecircuit interrupter is in the respective closed or open breakerposition; and a light guide mounted adjacent the opening within thehousing and configured to guide light from outside the housing onto theindicator, said light guide comprises a light tunnel having a lightentrance at the opening and extending within said housing, a light exitadjacent the indicator, and an interior reflective surface between thelight entrance and the light exit.
 2. (canceled)
 3. (canceled) 4.(canceled)
 5. The circuit breaker of claim 1 wherein said first indiciacomprises a first color and said second indicia comprises a secondcolor.
 6. The circuit breaker of claim 1 further comprising a pivot armhaving a first end cooperating with said actuator and a second endconnected to said indicator.
 7. The circuit breaker of claim 6 whereinsaid actuator includes a movable output and actuator plate connectedthereto, wherein said first end of said pivot arm is biased against saidactuator plate.
 8. The circuit breaker of claim 1 wherein said actuatorcomprises a magnetic actuator configured to receive an open or closesignal and in response, actuate the at least one circuit interrupterconnected thereto into the closed and open breaker positions.
 9. Thecircuit breaker of claim 1 wherein said frame is configured as anoutdoor circuit breaker or an indoor circuit breaker.
 10. The circuitbreaker of claim 1 wherein said at least one circuit interruptercomprises first, second and third single-phase circuit interruptersmounted within the interior compartment, each. having the closed andopen breaker positions, and said actuator comprises first, second andthird actuators connected to said first, second and third single-phasecircuit interrupters, respectively.
 11. The circuit breaker of claim 10wherein the indicator comprises first, second and third indicatorsconnected to said first, second and third actuators, respectively, andthe opening comprises first, second and third openings formed on thehousing and aligned with said first, second and third indicators,respectively.
 12. A circuit breaker, comprising: a frame defining ahousing having an interior compartment; at least one circuit interruptermounted within the interior compartment and having closed and openbreaker positions; an indicator operatively connected to said at leastone circuit interrupter and movable between first and second positionscorresponding to the respective closed and open breaker positions, saidindicator having a first indicator surface having first indicia as afirst color indicative that the at least one circuit interrupter is inthe closed breaker position and a second indicator surface having secondindicia as a second color indicative that the at least one circuitinterrupter is in the open breaker position; an opening formed on thehousing and aligned with the indicator to expose for view the respectivefirst or second indicia when the at least one circuit interrupter is inthe respective closed or open breaker position; and a light guidemounted adjacent the opening within the housing and configured to guidelight from outside the housing onto the indicator, said light guidecomprises a light tunnel having a light entrance at the opening andextending within said housing, a light exit adjacent the indicator, andan interior reflective surface between the light entrance and the lightexit.
 13. (canceled)
 14. (canceled)
 15. The circuit breaker of claim 12comprising a pivot arm connected to said indicator.
 16. (canceled) 17.(canceled)
 18. The circuit breaker of claim 12 wherein said frame isconfigured as an outdoor circuit breaker or an indoor circuit breaker.19. (canceled)
 20. The circuit breaker of claim 12 wherein said at leastone circuit interrupter comprises first, second and third single-phasecircuit interrupters and said indicator comprises first, second andthird indicators operatively connected to said first, second and thirdsingle-phase circuit interrupters, respectively, and said openingcomprises first, second and third openings formed on the housing andaligned with said first, second and third indicators, respectively. 21.An outdoor circuit breaker, comprising: a frame defining a housinghaving an outer surface and interior compartment; at least one circuitinterrupter mounted within the interior compartment and having first andsecond terminals and closed and open breaker positions; first and secondterminal bushings mounted on the outer surface, each of the terminalbushings having a lower terminal end extending into the housing andelectrically connected to respective first and second terminals of thecircuit interrupter; an actuator mounted within the interior compartmentand connected to said at least one circuit interrupter and configured toactuate the at least one circuit interrupter into the closed and openbreaker positions; an indicator and a pivot arm having a first endcooperating with said actuator and a second end connected to saidactuator, said indicator movable between first and second positionscorresponding to the respective closed and open breaker positions, saidindicator having a first indicator surface having first indiciaindicative that the at least one circuit interrupter is in the closedbreaker position and a second indicator surface having second indiciaindicative that the at least one circuit interrupter is in the openbreaker position; an opening formed on the housing and aligned with theindicator to expose for view the respective first or second indicia whenthe at least one circuit interrupter is in the respective closed or openbreaker position; and a light guide mounted adjacent the opening withinthe housing and configured to guide light from outside the housing ontothe indicator, said light guide comprises a light tunnel having a lightentrance at the opening and extending within said housing to a lightexit adjacent the indicator, and an interior reflective surface betweenthe light entrance and the light exit.
 22. (canceled)
 23. (canceled) 24.(canceled)
 25. The circuit breaker of claim 21 wherein said firstindicia comprises a first color and said second indicia comprises asecond color.
 26. The circuit breaker of claim 21 wherein said actuatorincludes a movable output and actuator plate connected thereto, whereinsaid first end of said pivot arm is biased against said actuator plate.27. The circuit breaker of claim 21 wherein said actuator comprises amagnetic actuator configured to receive an open or close signal and inresponse, actuate the at least one circuit interrupter connected theretointo the closed and open breaker positions.
 28. The circuit breaker ofclaim 21 wherein said at least one circuit interrupter comprises first,second and third single-phase circuit interrupters mounted within theinterior compartment, each having the closed and open breaker positions,and said actuator comprises first, second and third actuators connectedto said first, second and third single-phase circuit interrupters,respectively.
 29. The circuit breaker of claim 28 wherein said indicatorcomprises first, second and third indicators connected to saidrespective first, second and third actuators, and said opening comprisesfirst, second and third openings formed on the housing and aligned withsaid first, second and third indicators, respectively.